Mechanical stoker.



2 Sheets-$heet l.

Patented Jan. 28, I902.

T. N. HARRISON. MECHANICAL STOKEB.

(Application filed Oct. 21, 1901.)

(No Model.)

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. No. 69|,764. Patented Jan. 28, I902.

T. vN. HARRISON. MECHANICAL STOKER.

(Application Med Oct. 21, 1901.)

2 SheetsSheat 2.

(No Model.)

mm k r 6 0 wA I Witnesses;

n1: NORRIS virus 00.. PHoTouTflQ. WASHINGTON, 0 c4 UNITED STATES PATE T Grease;

I THEODORE N. HARRISON, OF MIDDLETOWN, OHlO.

MECHANICAL STOKER.

SPECIFICATION forming part of'Letters Patent No. 691,764, dated January as, 1 902,

I Application filed October 21, 1901. Serial No. 79,338. (No model.) I i oflice address No. 158 Baltimore street, Middletown, Ohio,) have invented certain new and useful Improvements in Mechanical Stokers,

of which the following is a specification.

Thisinvention, pertaining to improvements in mechanical stokers for furnaces, steamboilers, and the like, will be readily understood from the following description, taken in connection with the accompanying drawings, in which- I Figure 1 is a vertical longitudinal section of my improved stoker shown as applied to a boiler-furnace, the section being in the plane of line or of other figures; Fig. 2, a plan of the same, parts appearing in horizontal section in the planes of lines 12 and 0, two of the floor-plates and one of the tube-tops being removed; Fig. 3, a Vertical transverse section in the plane of line d; Fig. 4, a plan, on an enlarged scale, reproducing the right-hand portion of Fig. 2 with the bin-floor removed; Fig. 5, a vertical transverse section of the tube in. the plane of line 6; Fig. 6, a vertical transverse section in the plane of line f; and Fig. 7, a side elevation of a section of the feed-worm, an end portion appearing in vertical longitudinal section.

In the drawings, 1 indicates the furnacefront; 2, the bridge-wall; 3, that portion'of the boilerover the furnace; 4, the stoker-.

basin, the same being in the form of a deep rectangular trough, with its rima't the gratelevel and with its base well below the level of the floor of the fire-room, this basin being disposed within the furnace and extending, preferably, fore and aft from the front to the rear wall thereof, the general form and disposition of this basin being not unusual; 5, the hollow wall of the Stoker-basin, the same being adapted, as usual, to receive air from suitable pressure means and discharge the same inwardly to the basin at ports around thegrates or plates flooring the furnace alongside the stoker-basin, these plates being dead plates or grates to such extent as may be desired; 9, the fire-doors through the furnacefront over the grate to serve in manipulatin case of hand-firing; 10, the ash-doorsleadand at the sides of the Stoker-basin; 11, the ash-chamber; 12, a wall of the fire-room opposite to and distant from the front wall 1 of room and preferably substantially opposite trough disposed below the level of the fireroom floor and extendiugfrom near the'wall 12 to an opening in the front end of the ation toward the wall 12 of the floor of the s tokerbasin and being formed of lengthwise sections united at their ends, as by flanges and bolts, so as to form a straight continuous trough; 15, the top of the trough, the same being formed in lengthwise sections and securely bolted by flanges to the top of the trough, so as to complete the trough into a circular tube entirely below the level of the fire-room floor; l6, floor-plates in lengthwise sections covering over the trough structure ',and giving to the fire-room floor an even surface over the trough; 17, an uncovered portion of the trough at its end nearer wall 12; 18, a bin-floor or slope-board extending from wall 12 below opening 13 downwardly to the fire-room floor at a point corresponding with the outer end of uncovered portion 17 of the trough, this floor forming a slope down which the coal may slide on its way to the trough; 19, a check-board disposed parallel with wall 12 and crossing the line of the trough at the inner endof the uncovered portion 17 of the trough, this check-board serving to arrest the fuel sliding down the slope-board; 20, the coalbin considered as a whole, the same being formedby floor 18, check-board 19, suitable side boards, the uncovered portion of the trough, and portions of the lire-room floor at each side of the trough; 21, a triangular chamber under slope-board 18; 22, a pit in that the front of the furnace; 14, a semicircular Stoker-basin, this trough forming a continu-t a 5'5 ing the fuel or ashes or to serve as fuel-doors I ing to the ash-chamber below the gratelevel I the furnace; 13, an opening in the wall 12 at some distance up from the floor of the fire- I portion of this chamber nearest the wall 12; 23, a feed. worm or screw journaled in and fitting the trough and extending through the uncovered portion 17 thereof and entirely through the covered portion thereof and projecting well into the base of the stoker-basin, the main portion of this screw being of uniform diameter, that end at the uncovered portion 17 of the trough being, however, tapered, so as to be smaller at the outer end of the uncovered portion of the trough, the opposite end of this screw where it enters the Stokerbasiu being reversely tapered, so as to be smallest at its extreme end in the basin, this screw being formed in lengthwise sections properly coupled together; 24, gearing and transmitting mechanism connected with the outer end of the screw 23 and located in the chamber 21 and adapted to serve in giving rotary motion to the screw, the gearing being illustrated as ,a transverse shaft disposed above the floor of the fire-room and connected by worm and worm-gear with the screw; 25, an engine or other motor for producing the retation of the screw; 26, a non-circular socket in one end of each section of the screw 23; 27,21 corresponding non-circular tenon at the opposite end of the section of the screw, the sockets and tenons serving as means by which the sections of the screw are coupled up into acontinuous screw; 28, the handle for regulating the damper 7 of the air-conduit, and 29 the general fire-room floor.

Referring to Fig. l, the coal is to be deposited in bin 20 most conveniently by taking it from a car exterior to the fire-room and .throwing it into the bin through opening 13. The coal forms a heaping pile in the bin, the base of the pile settling into the trough at opening 17. The screw, in constant motion, conveys the coal along below the level of the fireroom floor and into the stoker-basin, which becomes finally filled and heaped up under pressure from below, the combustion taking place at the top of the fuel in the Stoker-basin, where it is supplied with air under pressure through the air-ports in the rim thereof. If grates are employed alongside the stokerbasin,the ashes, moved sidewise from the mass of burning fuel, may go down into the ashpit and be removed through the ash-doors at the front of the furnace, which is entirely clear and unobstructed. If dead-plates entire are used instead of grates at the sides of the stoker, then the ashes may be dumped from these plates to the ash-pit or they may be removed through the fire-doors or through side doors provided in the furnace-walls for the purpose. The chamber 2L under the slope-board 18 provides a well-protected space for the gearing, and the pit 22 gives standingroom for a workman when inspecting and oiling the gearing. The tapering of the screw at the opening 17in the trough causes its lifting tendency to be lessened at the initial end of the screw, thus causing the screw to gradually increase its generalconveying effect at the opening and prevent the coal between its spirals from forming a solid rotary core working under the superincumbent mass.

I claim as my invention- 1. In a stoker, the combination, substantially as set forth, of a furnace, a rectangular Stoker-basin disposed therein with its rim at the grate-level and havinga semicircular floor disposed below the level of the fire-room floor, a circular tube disposed concentric with the floor of the stoker-basin and extending longitudinally therefrom below the fire-room floor and to a point distant from the front of the furnace, a longitudinal openingin the top of said tube at its end farthest from the furnace, a coal-bin provided with a slope-board and a cheek-hoard at the opposite ends of said longitudinal opening, a feed-screw disposed Within said tube and extending continuously through the same and lengthwise of said longitudinal opening therein and lengthwise into the stoker-basin, and mechanism for rotating said feed-screw.

2. In a stoker, the combination, substantially as set forth, of a furnace, a rectangular Stoker-basin disposed therein with its rim at the grate-level and having a semicircular floor disposed below the level of the fire-room floor, a circular tube disposed concentric with the floor of the Stoker-basin and extending longitudinally therefrom below the fire-room floor and to a point distant from the front of the furnace, a longitudinal openingin the top of said tube at its end farthest from the furnace, a coal-bin provided with a slope-board and a check-board at the opposite ends of said longitudinal opening,a feed-screw disposed within said tube and extending continuously through the same and lengthwise of said longitudinal opening therein and lengthwise into the Stoker-basin the end of said screw being tapered at said longitudinal opening so as to be smaller at the end of said opening farthest from the furnace, and mechanism for rotating said screw.

3. In a stoker, the combination, substantiall y as set forth, of a furnace, a rectangular Stoker-basin disposed therein with its rim at the grate-level and having a semicircular floor disposed below the level of the fire-room floor,

a circular tube disposed concentric with the floor of the Stoker-basin and extending longitudinally therefrom below the fire-room floor and to a point distant from the front of the furnace, a longitudinal opening in the top of said tube atits end farthest from the furnace, a coal-bin provided with a slope-board and a check-board at the opposite ends of said longitudinal opening, a feed-screw disposed within said tube and extending continuously through the same and lengthwise of said 1ongitudinal opening therein and lengthwise into the Stoker-basin, gearing disposed below said slope-board and connected with said screw, and mechanism for giving rotary motion to said gearing and screw:

4. In a stoker, the combination, substantially as set forth, of a furnace, a rectangular stoker-basin disposed therein with its rim at the grate-level and having a semicircular floor disposed below the level of the fire-room floor, a semicircular trough extending endwise from said stoker-basin below the fire-room floor and forming a prolongation of the semicircular floor of the basin to a point distantly in front of the furnace, a coal-bin disposed over the end of said trough distant from the furnace so as to leave a clear space between said coalbin and the front of the furnace, sectional cover-work for said trough at the portions thereof between the coal-bin and the furnacefront, said trough and cover-work producing a circular tube extending between the bin and Stoker-basin, a feed-screw disposed within the trough and extending the length thereof and endwise into the stoker-basin, and mechanism for rotating said feed-screw.

5. In a stoker, the combination, substantially as set forth, of a furnace, a rectangular stoker-basin disposed therein with its rim at the grate-level and havinga semicircular floor disposed below the level of the fire-room floor, a semicircular trough extending lengthwise from said Stoker-basin below the fire-room floor and forming a prolongation of the semicircular floor of the basin to a point distantly in front of the furnace, a coal-bin disposed over the end of said trough distant from the furnace so as to leave a clear space between said coal-bin and the front of the furnace, a section al semicircular trough-cover secured to said trough and covering the same between the coal-bin and the furnace-front, sect-ion floor-plates disposed over said trough-cover, a feed-screw disposed within said trough and extending the length of the same and endwise into the Stoker-basin, and mechanismfor giving rotation to said screw.

6. In a stoker, the combination, substantially as set forth, of a furnace, a rectangular Stoker-basin disposed therein with its rim at the grate-level and having a semicircular floor disposed below the level of the fire-room floor, a semicircular trough extending lengthwise from said Stoker-basin below the fire-room floor and forming a prolongation of the semicircular floor of the basin to a point distantly in front of the furnace, a coal-bin disposed over the end of said trough distant from the furnace so as to leave a clear space between said coal-bin and the front of the furnace, a sectional semicircular trough-cover secured to said trough and covering the same between the coal-bin and the furnace-front, section floor-plates disposed over said trough-cover, a continuous feed-screw formed of sections with tenon-and-socket joints and disposed Within said trough and extending the length of the same and endwiseinto the stoker-basin,

and mechanism for giving'rot-ation to said feed-screw. r

7. -In a stoker, the combination, substantially as set forth, of a furnace, a rectangular Stoker-basin disposed therein with its rim at the grate-level and havinga semicircular floor disposed below the level of the fire-room floor, a circular tube disposed concentric with the floor of the stoker-basin and extending longitudinally therefrom below the fire-room floor and to a point distant from the front of the furnace, a longitudinal opening in the top of said tube at its end farthest from the furnace,

a wall parallel with the furnace-front across.

.screw disposed within said tube and extending the length of said longitudinal opening and projecting end wise into the stoker-basin, and mechanism for giving rotation to said screw.

8. In a stoker, the combination, substantially as set forth, of a furnace, a rectangular Stoker-basin disposed therein with its rim at the grate-level and havinga semicircular floor disposed below the level of the fire-room floor, a circular tube disposed concentric with the floor of the stoker-basin and extending longitudinally therefrom below the fire-room floor and to a point distant from the front of the furnace, a longitudinal opening in the top of said tube at its end farthest from the furnace, a wall parallel with the furnace-front across the end of said tube and having an opening above the level of the fire-room floor, a slopeboard extending from said wall below said opening therein to the nearer end of said longitudinal opening in thetube, a check-board across the end of said longitudinal opening farthest from said wall, a continuous feedscrew disposed within said tube and extending the length of said longitudinal opening and projecting endwise into the stoker-basin, gearing disposed below said slope-board and within said wall and connected with said screwand mechanism for driving said gearing and screw. 7

9. In a stoker, the combination, substantially as set forth, of a furnace, a rectangular stoker-basin disposed therein with its rim at the grate-level and havinga semicircular floor disposed below the level of the fire-room floor, a circular tube disposed concentric with the floor of the stoker-basin and extending longitudinally therefrom below the fire-room floor and to a point distant from the front of the furnace, a'longitudinal opening in the top ofsaid tube at its end farthest from the furnace, a wall parallel with the furnace-front across the end of said tube and having an opening above the level of the fire-room floor, a

within said Wall and connected with said 10 screw, mechanism for driving said gearing and screw, and a pitin the fire-room floor between said wall and gearing.

THEODORE N. HARRISON.

Witnesses:

J3. HARWITZ, W. T. HARRISON. 

